On Tuesday, the federal government unveiled its National Alzheimer’s Plan to find effective ways to prevent and treat dementia and Alzheimer’s by 2025. On Wednesday, the plan’s scope became clearer as news broke of federal funding for an unprecedented drug trial: participants who are genetically guaranteed to get Alzheimer’s but do not yet have symptoms will receive medication intended to prevent the onset of Alzheimer’s.

As part of the National Alzheimer’s Plan, the National Institutes of Health (NIH) awarded a $16 million grant to Banner Alzheimer’s Institute in Arizona to fund the Alzheimer’s Prevention Initiative (API), which will study whether a plaque-fighting treatment can prevent the disease. The trial will take place in Medellín, Colombia as well as select sites in North America. The majority of the study participants will come from an extended family of 5,000 people living in Medellín who are considered part of the world’s largest family affected by Alzheimer’s. The New York Timesreports the family members have a specific genetic mutation that causes symptoms of cognitive impairment around age 45, then full dementia around age 51.

The initial trial will enroll 300 family members whose symptoms are still years away from developing. “Once symptoms begin to manifest, the disease may have already progressed to a point at which it is too late for any treatment to be effective,” the API writes.

The study will last five years, but within two years, some tests may determine whether the drug helps stave off cognitive decline, Dr. Eric M. Reiman, executive director of the Banner Alzheimer’s Institute and a study leader, told the Times.

“We believe this is the first prevention trial in cognitively normal people who, based on their genetic background, are destined to develop Alzheimer’s disease,” Reiman told AZCentral. “This study has the potential to launch a new era of Alzheimer’s prevention research.”

The anti-amyloid treatment that will be used in the trials is called crenezumab, and comes from the American drug manufacturing company Genentech. The drug acts on a substance known as ABeta, which is a major component of the brain plaque that comes with Alzheimer’s disease, ABC News reports. “The [genetic] mutation causes a more rapid accumulation of ABeta in the brains of people who have it. It activates the enzyme that produces the ABeta,” Richard Scheller, executive vice president of research and development at Genentech, told ABC. The trial will help determine how large a role ABeta plays in the disease.

Funding for the trial is provided by the $16 million NIH grant, $15 million in donations from the Banner Alzheimer’s Foundation and about $65 million from Genentech.

The study is expected to begin in 2013. Half of the genetic carriers in the Colombian trial will take crenezumab and another 100 will be given a placebo treatment. Another 100 Colombians who are not carriers of the gene also will receive a placebo.

If the drug is successful, it could lead to ground-breaking treatments for people at high genetic risk of developing the disease. In the meantime, API is encouraging anyone over 18 who is interested in participating in Alzheimer’s prevention studies to register with the Alzheimer’s Prevention Registry. Although no trials are currently underway, the API says recruiting and retaining trial participants is one of the biggest obstacles for Alzheimer’s treatment and prevention trials, and signing up can advance future research.

“We have a chance to test and to give people access to the most promising treatments,” Reiman told AZCentral. “We have an extraordinary need to advance the fight against Alzheimer’s disease.”